#! /usr/bin/python3
# coding=utf-8
# @Time: 2023/1/4 11:25
# @Author: Loneliness Burial


import math

radius = float(input('请输入圆的半径: '))
perimeter = 2 * math.pi * radius
area = math.pi * radius * radius
print('周长: %.2f' % perimeter)
print('面积: %.2f' % area)
